The West Wing star will be playing a female executive who suddenly becomes a stay-at-home mum, according to Entertainment Weekly.
The untitled pilot has been written and produced by The New Adventures of Old Christine showrunner Kari Lizer.
The 43-year-old actress has just finished a five-season run on the popular USA drama In Plain Sight.
She has also wrapped filming on upcoming movie Should've Been Romeo, starring alongside Kelly Osbourne.
McCormack gave birth to her third daughter in September.
Watch a trailer for Mary McCormack's In Plain Sight below: